Changing soil acidity using biological fertiliser programs like BSA’s can be an effective alternative to lime, dolomite lime, or gypsum.

Our studies go back to 2015 to investigate the belief that more inputs (N,P,K) were needed to gain the same rate of pasture growth and whether biological nutrient exchange could reduce the reliance on synthetic fertilisers.

The BSA  Program

•                     MSA live bacteria with biostimulants

•                     Suplemented with MSA Carbon and a combination of bias and non bias MSA products

Application method: The products were mixed in a boom sprayer and applied as ground cover twice per year.

Trial sites varied from 50 to 100 acres with control areas placed adjacent to the trial sites. The dugout soil was examined to check the root condition as well as signs of nodulation on the clover roots. An earthworm count was also performed and an examination to see if there were any signs of fungi activity by observing white filaments within the root zone of the pasture.

Soil Improvements

At the start of the project, we aimed to increase grass growth, increase biological activity, and to produce healthier pastures and livestock. Our investigation into the introduction of soil biology to our trial sites proved to have a greater impact than we had expected.

Better pH: An increase was achieved throughout the trial sites equivalent to approx. 1 tonne/ha of lime application to the clay soil.

Grass Growth: There was a difference in the growth of the grass in the treated paddocks, and this growth was a darker green. The paddocks reached the three-leaf stage sooner than the untreated paddocks and produced growth further into the summer period, due to the better soil and greater depth of topsoil retaining moisture.

It was also noted that the paddocks treated with the MSA Program produced more round bales per Ha than the untreated paddocks.

‍Hot Summer: It was thought the long and hot summers would kill the bacteria as the moisture level became low and the soil was just dust for several months. We note, that the biological levels in the soil were maintained and the activity through the microscope was consistent with the samples when the soil had moisture.

Effects of Fertiliser Application: We noticed that the same paddock response was achieved with a lesser rate of fertiliser application with the rate of application of (SSP) reducing from 200kg/Ha to 80kg/Ha without any visual difference to the pasture growth.

Urea: A similar trial was conducted using urea used to boost pasture growth in the Autumn to provide a feed wedge for winter. Two trial paddocks were treated with 80kg/Ha of urea and again there was no negative effect on the biological activity found in the samples taken.

Brix Readings: The Brix reading indicated that healthier and more nutrient pastures were being produced and more nutrients were available to the livestock eating grass.

Better pH: An increase was achieved throughout the trial sites equivalent to approximately 1 tonne/ha of lime application to the clay soil.

Soil Structure: All treated soils showed a significant increase in the depth of topsoil.

With one application of the BSA Program, an average of 15mm of topsoil was added to the soil and with three applications over 55mm of topsoil. In all cases the soil was more friable and had better root structures (density and length).

The worm activity in treated paddocks increased significantly which probably helped break up the hard-packed layers of the soil. The water infiltration and retention within the soil also increased,  this has been evident from the pasture response after summer rain and the extended growth experienced going into the summer months.

Conclusions 2015 – 2020

The biggest change was the improvement in the texture of the soil – the soil changed from a tight clay to a darker more friable soil which retained moisture.

The topsoil depth increased as did the root penetration and root density, producing better pasture.

The improvements were most noticeable during periods of low rainfall where the pasture would normally suffer moisture stress. It was also noted that the clover had a better root structure and a greater number of root nodules.

Results from soil tests also indicated that the pH of the soil was changing. The average value of the pasture Ph was 5.6 at the start of the trial and 6.1 at the end with no lime added.

There was also more evidence of fungi activity and a better nodulation rate on clovers.

The available nutrients in the soil were also rising (particularly phosphorus). The active biology was breaking the tight chemical bonds in the soil releasing more available nutrients to the pasture root zone.

The increase in the biological activity is designed to promote not only the bacterial strains added to the soil but to feed and promote the growth of the existing microorganisms in the soil.

The Brix readings in the treated paddocks were 2 points higher than the untreated paddocks, showing that the sugars and nutrients had increased.

A feed test was carried out to ascertain the feed value of the pasture which confirmed that the feed value of the pasture was very high (one of the best seen) and provided excellent nutrition for the cattle.

Farmer Observations

The farmers using the program were asked for their observations from the trial with the following results:

•                          Faster grass growth after rain

•                          More hay produced from treated paddocks

•                          Less fertiliser is required to produce good grass growth

•                          Cost effective

•                          Prolonged grass growing season

•                          Increased number of earthworms in the paddock

•                          The cattle seem happier and healthier, with fewer foot problems

•                          Less water runoff during large rain events

Cost Effective: The program gave better results and cost about $68.50 + GST per Ha, with fertiliser application(SSP) rates being cut from 200kg/Ha to 80Kg/Ha with no visual difference to grass growth.

Savings on the use of fertiliser with the cost of SSP @ $459 + GST per tonne was about $55 ex GST + spreading costs per Ha application. 

Summary

From the trials carried out it is evident that the soil properties improved dramatically, particularly the soil structure, topsoil depth, and available nutrients which produced healthy and vigorous grass growth.

The conclusion is that the program increased soil structure as a determinant to better soil health, which in a short period allowed for the normal fertiliser regime to be cut significantly (and in most cases by half) while maintaining greater pasture production.